1. Field of the Invention
The present invention relates to a device for sampling atmospheric conditions at a test location for subsequent analysis.
2. State of the Art
It is known to provide a sampling device in the form of an elongate tube containing a quantity of adsorbing material. At least one end of the tube is provided with a removable cap which allows the interior of the tube, once exposed to the surrounding atmosphere at a test site, to be sealed prior to the analysis of its contents.
Analysis of the contents of the tube involves removing the cap from the end of the tube, applying heat to the tube to release adsorbed substances from the adsorbing material and driving the released substances out of the tube using a flow of gas.
However, a difficulty arises in labelling such tubes, in a convenient manner, such that they may be readily distinguished from one another at an analysis site and such that the tubes may be subsequently re-used.
We have now devised an arrangement which overcomes the limitations of existing sampling devices.
In accordance with the present invention, there is provided a sampling device comprising an elongate tube and an identification device comprising a transponder which is removably attached to the tube by means of a clip.
The identification device may thus be removed from the tube prior to analysis and/or replaced between successive sampling operations.
Preferably the transponder is attached to the tube such that it does not directly contact the exterior surface of the tube. The transponder is thus thermally isolated from the tube to a substantial extent, thereby allowing the identification device to remain attached to the tube during analysis.
Preferably the tube is formed with a reduced diameter portion within which the clip is attached to inhibit movement of the identification device along the length of the tube.
Preferably the reduced diameter portion is situated towards one end of the elongate tube, so that the opposite end of the tube may be heated during analysis without damaging the transponder.
Preferably the clip comprises a first part for attaching to the tube and a second part for attaching the transponder to the first part, thereby allowing a spent transponder to be readily replaced without sacrificing the clip.
Preferably the first part comprises a pair of resilient arms which engage opposite sides of the tube and connecting portions which extend between the two arms at spaced apart points along the axis of the tube, with the second part comprising a generally U-shaped member which clips around the transponder and the two connecting portions of the first part to hold the transponder against the undersides of those portions. The transponder is thus substantially encapsulated, with the gap between the two connecting portions providing a window through which the transponder may be read.
Preferably the resilient arms are arcuate in form and engage the sides of a cylindrical tube.
The clip, or at least the first part of the two part clip described above, is preferably formed from a material having low thermal conductivity, thereby further thermally isolating the transponder from the tube.
The sampling tube may be formed from glass or from a metallic material.
Also in accordance with the present invention, there is provided an identification device comprising a transponder and a clip for attaching the transponder to an elongate sampling tube.
Further in accordance with the present invention, there is provided a method of labelling a sampling tube comprising removably attaching a transponder to the tube by means of a clip.
An embodiment of the present invention will now be described by way of an example only and with reference to the accompanying drawings, in which: